Patent GB-1463372-A (GB)
Title: Compressors
IPC: F04B27/06
Filed: 1974-01-22
Abstract: 1463372 Reciprocating piston compressors W FRANKE 22 Jan 1974 [23 Jan 1973] 03262/74 Heading F1N In a single or multi-cylinder compressor comprising a piston 13, Fig. 3, reciprocable in a radial cylinder 49 in a rotor assembly 46 mounted in a housing 1, the piston 13 has opposed inclined guide surfaces between which is slidably disposed a fixed crank-pin 32, adjustment of the angular position of the crank-pin 32 about the axis of rotation of the rotor enabling the stroke characteristics of the piston to be altered. A block 26 is journalled on the crank-pin 32 and makes sliding contact with the guide surfaces. The piston 13 performs two-stage compression, gas being admitted to the high-pressure end 47 of the cylinder 49 through an inlet port 51 and being supplemented by gas previously compressed in the opposite end 48 of the cylinder and transferred to the end 47 when the piston 13 uncovers transfer ducts 50, 138. Gas enters the low-pressure end 48 of the cylinder through one-way valves 54, 55 during the final compression of the gas in the cylinder end 47 and delivery through an outlet port 53. Additionally a port 56 in communication with the transfer duct 50 and arranged to align at the appropriate moment with a port 57 in the housing 1 is provided for the admission of further gas to the low-pressure end 47. Seals 60 prevent the escape of gas from the cylinder 49. In an alternative construction, Fig. 5 (not shown) the piston 13 is stepped and a one-way valve (68) admits air into the low-pressure end 48 from the inlet port 51, the latter being located in a different transverse plane from the outlet port 53 whereby the high-pressure end 47 (smaller end) only receives gas through the transfer ducts. Fig. 6 shows a multi-piston compressor comprising two pairs of opposed pistons disposed at right angles to each other. Each piston is connected by a piston-rod 5 or 6 to its opposite piston, the piston-rods passing through partitions 76, 77 and carrying the inclined guide surfaces therebetween. A crank-pin 30 is received between the guide surfaces and is fixed to an axial shaft 31 having a lever 42 locatable in any one of a number of angular positions by a pin 143 inserted into a selected one of a number of angularly spaced holes 142 in the housing 1. Gas enters the outer ends of the cylinders through a peripheral inlet port (70) and is transferred through transfer passages 94, 95 to the inner ends for final compression and discharge through passages 97, 102, 101. The axes of the cylinders are shown disposed in spaced parallel planes but by bending the central regions of the piston-rods, Fig. 1 (not shown) a compressor with co-planar cylinders may be produced. Moreover the transfer of gas from the outer to the inner ends of the cylinders is via an external passage (82), a cooler (83) and an end port (84) in the housing 1. In a further multicylinder construction, Fig. 9 (not shown), three opposed pairs of equi-angularly spaced pistons are provided. Each pair is composed of a large and a small piston. A fan (91) for forcing cooling air through holes (92, 93) in the housing 1 may be provided.